Subway sandwich chain founder and president Fred DeLuca made a recent dramatic appearance a year after being diagnosed with a very aggressive form of leukemia, The Post has learned.

DeLuca showed up at a large Subway franchisee meeting in Florida, a source at the meeting said. “He wouldn’t shake hands. He would fist-bump,” the source said.

Subway confirmed the appearance: “Fred’s doing really well and has been fully involved in the day-to-day business. In mid-January, to reduce the spread of germs, Fred used the ‘fist bump’ when greeting people, but now that it’s nearly 6 months post-[treatment], he’s back to the traditional handshake.”

Brooklyn-born DeLuca has largely run the national chain since co-founding it 46 years ago. During the last year, he has been making some company decisions from a hospital bed, sources said.

Subway claims it is the world’s largest restaurant chain, with more than 40,000 locations in 100 countries.

There are no natural heirs to take over, leading to speculation that he will bring the chain public or sell it privately.